China, North Korea's main benefactor and ally, has avoided joining the chorus of nations denouncing the North for such acts, despite Pyongyang's attacks on Seoul since the Korean War ended in a truce in 1953.
The Chinese stance was back in the spotlight in 2010 when Beijing refused to openly censure North Korea for sinking a South Korean warship, killing 46 sailors.
"It is problematic because China has appeared to take an attitude of protection and support for North Korea, while the North sometimes makes military provocations and implements some incorrect policies," Lee Kyu-hyung, Seoul's top diplomat to Beijing, told Yonhap News Agency in an interview.
South Korea will "continue to raise the issue and make efforts to persuade" China to change that attitude, Lee said.
"China has responsibility as one of the world's leading nations," Lee said. "When North Korea makes an action that violates the rules of the international community, there is a policy and attitude that China should take beyond their bilateral relations."
Ambassador Lee Kyu-hyung (Yonhap file photo)
The ambassador said South Korea and China have a "mutual interest in peace and stability on the Korean Peninsula," as North Korea undergoes a sensitive transition of dynastic power following the Dec. 17 death of Kim Jong-il.
Since the sudden demise of Kim, his youngest son and designated successor has taken the helm of North Korea and the leadership transition appears to be running smoothly. Experts remain wary, however, on whether the transfer of power to the inexperienced Kim Jong-un, believed to be in his late 20s, will be stable.
President Lee Myung-bak will make a state visit to China next week to hold summit talks with his Chinese counterpart Hu Jintao, in a meeting expected to focus on keeping stability on the Korean Peninsula.
Lee will arrive in Beijing on Monday for a three-day visit, during which he will meet with Hu to discuss ways to enhance the strategic partnership between the two countries and exchange views on pending issues, officials said.